What was a typical limit of passenger cars for a standard GP-7 on a level route. In particular PRR engines in Valpo to Chicago service if anyone has any specifics. Thank you
ndbprr What was a typical limit of passenger cars for a standard GP-7 on a level route. In particular PRR engines in Valpo to Chicago service if anyone has any specifics. Thank you
I cannot offer any insight into the specific prototype situation you described.
But, in general terms, a GP-7 has similar hp and tractive effort when compared to a medium sized 4-6-2.
So, based on that alone, 10-12 heavyweight cars would be a conservative consist for a single GP-7 in relatively flat territory. Grades might be a different story.
Passsenger trains tended to be over powered to allow for higher speed gearing and to allow faster acceleration.
Sheldon
Hello All,
Full disclosure: I don't run passenger service or GP7s on my HO pike.
Passenger service requires some form of electrical or steam generation from the motive power- -from a HEP (Head End Power) locomotive or a Steam Generator Car- -depending on the era you are modeling.
I don't know if any GP7s were fitted with steam generators.
From my observations- -prototypical passenger service with GP7s would require an "MU" or consist to accommodate the steam generator car along with combine/ baggage, and other "service" cars along with the passenger cars.
These "extra" cars should be factored into the motive power you choose to run with the passenger cars.
I suspect that on a straight and level track, a minimum of two (2) GP7s would be required to pull a train of 4-5 "free rolling" non-lit, passenger cars along with the requisite "service" cars mentioned above.
Hope this helps.
"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"
GP-7's were most definitely fitted with steam generators in the short hood and some had their air tanks mounted on the long hood to provide more room for water tanks underneath. Oftened reffered to as 'Torpedo Tube' geeps. CNW and Soo both had them.
The Soo used a combination of Geeps and F units to pull the 10-12 car Laker or Winnepeger on relatively flat ground.
Scott Sonntag
Lakeshore SubGP-7's were most definitely fitted with steam generators in the short hood and some had their air tanks mounted on the long hood to provide more room for water tanks underneath.
Thank you for the clarification!
Back on the old New Haven, an FL9 (1750hp) would be expected to handle 6-7 cars. This is on a line with no heavy grades.
A GP7 had slightly less horsepower (around 1500, I would think). So again, on a relatively level railroad, I'd expect it to be given no more than six or seven cars, with which to maintain "passenger train speeds".
Lakeshore Sub GP-7's were most definitely fitted with steam generators in the short hood and some had their air tanks mounted on the long hood to provide more room for water tanks underneath. Oftened reffered to as 'Torpedo Tube' geeps. CNW and Soo both had them.
The NP also had one GP-7 that had the torpedo tubes for passenger service as well.
GP7's had steam generators in the short hood.
If the railroad wanted more fuel or water capacity they would put the air tanks on the top. Some did, some used the smaller fuel tanks (RDG, PRR).
6-7 cars seems about right. A GP-7 could pull 20 cars but couldn't accelerate them fast enough to maintain a passenger schedule.
Dave H. Painted side goes up. My website : wnbranch.com
The B&O had 7 "torpedo tube" passenger GP-7's, which were set up to run long hood forward.
I have been told the original intent was two sets of two and a set of three. And great many pictures of them show them that way, two back to back or a set of three with the outer two facing away, effectively an ABA set.
But later especially there are a number of photos of them working alone as well.
It is my opinion that the early diesels were set up with long hood forward for one simple reason. Steam engines had the cab at the back of the boiler for the most part with the exceptions being the SP cab forwards and camelback engines. So it was a case of, "That's the way we have always done it". it certainly was a safer location for crews then up front.
ndbprr It is my opinion that the early diesels were set up with long hood forward for one simple reason. Steam engines had the cab at the back of the boiler for the most part with the exceptions being the SP cab forwards and camelback engines. So it was a case of, "That's the way we have always done it". it certainly was a safer location for crews then up front.
Early diesels were box cabs, with the cabs at the "forward" ends. Then center cabs, then end cab switchers. Then streamliners came out with forward cabs. After that were the road switcher types, like GP and RS series.
MidlandMike ndbprr It is my opinion that the early diesels were set up with long hood forward for one simple reason. Steam engines had the cab at the back of the boiler for the most part with the exceptions being the SP cab forwards and camelback engines. So it was a case of, "That's the way we have always done it". it certainly was a safer location for crews then up front. Early diesels were box cabs, with the cabs at the "forward" ends. Then center cabs, then end cab switchers. Then streamliners came out with forward cabs. After that were the road switcher types, like GP and RS series.
Yes, but when ALCO and Baldwin introduced the road switcher they put the cab at the rear.
Baldwin put the cab at the extreme rear, ALCO had a lower short hood/long hood configuration, but the long hood was the "front" unless you ordered them other wise.
When EMD introduced the GP7, they were happy to build them either way, long hood forward or short hood forward.
Many east coast roads, and some mid west roads, ordered their earlist purchases set up long hood forward. Likely because that's the way the ALCO's were, and there was concern about grade crossing safety.
In the west, grade crossing safety seems to have been less of an issue, and western roads seemed to imbrace the short hood forward idea right away.
The visibility advantages of short hoods, and then low hoods, quickly took over by the early 60's.
I went through the October/November/December 1971 GP7 list in Extra 2200 South and the 1959 EMD Product Data and found the 42 original railroads that owned passenger GP7s. Here they are: Aberdeen & Rockfish 1, Santa Fe 21, Atlanta & St. Andrews Bay 2, ACL 24, B&O 7, B&M 23, MEC 10, CG 4, CNJ 13, Charleston & Western Carolina 2, C&O 14, C&NW 23, CB&Q 68, CRI&P 11, DL&W 5, ERIE 5, GA 12, A&WP 3, WRA 3, GN 9, IC 14, L&N 19, MKT 4, MP 52, NC&SL 5, NYC 78, P&LE 7, P&E 2, NP 1, PRR 8, Portland Terminal 1, RDG 7, RF&P 3, SLSF 53, SSW 1, SAL 33, SR 10, AGS 5, CNO&TP 6, GS&F 4, WAB 11, and CP 2. This 586 unit list includes three new frame rebuilds and six GP7s that had steam generators added by their owner. There may be additional GP7s that had steam generators added by their owner.
Ed in Kentucky
ATLANTIC CENTRALWhen EMD introduced the GP7, they were happy to build them either way, long hood forward or short hood forward. Many east coast roads, and some mid west roads, ordered their earlist purchases set up long hood forward. Likely because that's the way the ALCO's were, and there was concern about grade crossing safety. In the west, grade crossing safety seems to have been less of an issue, and western roads seemed to imbrace the short hood forward idea right away.
It's true GM would build them either way, but I believe the original blueprints (and GP7 demonstrators 100-200-300) show the short hood as the front.
I don't know if there's really one answer as to why each railroad did what they did. Great Northern and Northern Pacific were both western railroads covering similar territory (from the Misssissippi to the Pacific Ocean); GN ran it's early GPs and Alco RS-1/RS-3s long hood forward, NP ran their GPs and RS-3s short hood forward. Many railroads ran their RS-1/2/3 engines long hood forward, but their early GPs short hood forward.
I've heard speculation that railroads that ordered passenger GP7s were more likely to run long hood foward, since the steam generator was in the short hood, so it would be closer to the cars. But then several railroads that had passenger GPs (Soo Line, CNW) ran short hood forward...so there doesn't seem to be any connection.
Interestingly enough, New York Central GP7s and GP9s ran long hood forward - except for the engines used in their lines in Canada, on the Canada Southern. Those GPs were all short hood forward.
wjstix ATLANTIC CENTRAL When EMD introduced the GP7, they were happy to build them either way, long hood forward or short hood forward. Many east coast roads, and some mid west roads, ordered their earlist purchases set up long hood forward. Likely because that's the way the ALCO's were, and there was concern about grade crossing safety. In the west, grade crossing safety seems to have been less of an issue, and western roads seemed to imbrace the short hood forward idea right away. It's true GM would build them either way, but I believe the original blueprints (and GP7 demonstrators 100-200-300) show the short hood as the front. I don't know if there's really one answer as to why each railroad did what they did. Great Northern and Northern Pacific were both western railroads covering similar territory (from the Misssissippi to the Pacific Ocean); GN ran it's early GPs and Alco RS-1/RS-3s long hood forward, NP ran their GPs and RS-3s short hood forward. Many railroads ran their RS-1/2/3 engines long hood forward, but their early GPs short hood forward. I've heard speculation that railroads that ordered passenger GP7s were more likely to run long hood foward, since the steam generator was in the short hood, so it would be closer to the cars. But then several railroads that had passenger GPs (Soo Line, CNW) ran short hood forward...so there doesn't seem to be any connection. Interestingly enough, New York Central GP7s and GP9s ran long hood forward - except for the engines used in their lines in Canada, on the Canada Southern. Those GPs were all short hood forward.
ATLANTIC CENTRAL When EMD introduced the GP7, they were happy to build them either way, long hood forward or short hood forward. Many east coast roads, and some mid west roads, ordered their earlist purchases set up long hood forward. Likely because that's the way the ALCO's were, and there was concern about grade crossing safety. In the west, grade crossing safety seems to have been less of an issue, and western roads seemed to imbrace the short hood forward idea right away.
Yes, from everything I have seen/read, the default for the GP7 was short hood forward.
But at ALCO with the RS units, the default was long hood forward.
I think there was some tendancy like you describe with passenger geeps to be built long hood forward.
All the operators of passenger equiped EMD F units, E units, PA's all prefered to run the B units with the steam generator close to the A unit steam generator, so the same likely followed with passenger geeps.
The B&O ran theirs "back to back", short hood to short hood.
I'm sure the reasons, and the weight of the various combined reasons, was different for every road.
ATLANTIC CENTRAL wjstix ATLANTIC CENTRAL When EMD introduced the GP7, they were happy to build them either way, long hood forward or short hood forward. Many east coast roads, and some mid west roads, ordered their earlist purchases set up long hood forward. Likely because that's the way the ALCO's were, and there was concern about grade crossing safety. In the west, grade crossing safety seems to have been less of an issue, and western roads seemed to imbrace the short hood forward idea right away. It's true GM would build them either way, but I believe the original blueprints (and GP7 demonstrators 100-200-300) show the short hood as the front. I don't know if there's really one answer as to why each railroad did what they did. Great Northern and Northern Pacific were both western railroads covering similar territory (from the Misssissippi to the Pacific Ocean); GN ran it's early GPs and Alco RS-1/RS-3s long hood forward, NP ran their GPs and RS-3s short hood forward. Many railroads ran their RS-1/2/3 engines long hood forward, but their early GPs short hood forward. I've heard speculation that railroads that ordered passenger GP7s were more likely to run long hood foward, since the steam generator was in the short hood, so it would be closer to the cars. But then several railroads that had passenger GPs (Soo Line, CNW) ran short hood forward...so there doesn't seem to be any connection. Interestingly enough, New York Central GP7s and GP9s ran long hood forward - except for the engines used in their lines in Canada, on the Canada Southern. Those GPs were all short hood forward. Yes, from everything I have seen/read, the default for the GP7 was short hood forward. But at ALCO with the RS units, the default was long hood forward. I think there was some tendancy like you describe with passenger geeps to be built long hood forward. All the operators of passenger equiped EMD F units, E units, PA's all prefered to run the B units with the steam generator close to the A unit steam generator, so the same likely followed with passenger geeps. The B&O ran theirs "back to back", short hood to short hood. I'm sure the reasons, and the weight of the various combined reasons, was different for every road. Sheldon
The Rock Island approached Alco for a diesel that could be used in yard or road service. Alco designed the RS-1 by modifying their end cab switcher design. The long hood had been the front of the S-1 and they stayed with that with the RS-1 and subsequent road switchers.
Jeff
Steam generators were a catalog option on GP7s, and I know IC, MKT, and CP had them.
How you arranged the water for the SGs was interesting. The 'stock' option was to devote some of the fuel-tank space to water, but the specific use of 'torpedo' tanks on top of the long hood was certainly used (Ed will have pictures of IC 8800/8900s and others) to allow larger water capacity without affecting fuel range as much.
Staufer relates a potentially-relevant discussion of steam vs. GP train acceleration in Thoroughbreds (hint: the diesel never even accelerated the train to the reference speed by the next station...) And I think that was a GP9, with more nominal traction horsepower...
The N&W didn't hesitate to tie a single GP-9 onto the head of six cars:
,N.W GP-9 at Dearborn - Polk St station Chicago IL June 1976 by Mark LLanuza, on Flickr
While the Pennsy and P-C hedged their chances on the Valpo commuter run by assigning one Geep per two cars:
Penn Central GP-7's at Chicago IL 1976 by Mark LLanuza, on Flickr
As noted their 'loading' may have been so poor that in order to maintain anything close to passenger schedules they needed to be doubled up. Also in the P-C era it didn't hurt to have a backup engine as breakdowns on the road were somewhat frequent.
Hood-top air reservoirs on the B&O:
Thomas Underwood Coll B&O604 by John W. Barriger III National Railroad Library, on Flickr
Regards, Ed
deleted
Alton Junction
Early F-units were often run in pairs, an A-B set connected with a drawbar. Normally they were back-to-back; a quick way to tell is the ends with the roof fans will be close to each other. The steam boiler and water were in the area of the B unit where the cab would be in an A unit, so it would be towards the back of the A-B set...and closer to the passenger cars.
In my area, the GN ran both early RS and GP diesels long-hood forward, and NP ran both short-hood forward. I believe the other 7 (CB&Q, M-St.L, CNW, CGW, CRIP, MILW, and SOO) ran their early GPs short-hood forward, and their early Alco RS's long-hood forward. So as Sheldon points out, it may just have been more how the engines were originally designed than anything else.
(p.s. it would be interesting to try to do a calculation of how many early GPs were set up long-hood forward. Although I think the percentage of railroads that ran them short-hood first is higher, it could be the percentage of GPs built to run long-hood forward were higher, since two huge railroads (Pennsy and NYC) ran them long-hood first.)
[/quote]
wjstix Early F-units were often run in pairs, an A-B set connected with a drawbar. Normally they were back-to-back; a quick way to tell is the ends with the roof fans will be close to each other. The steam boiler and water were in the area of the B unit where the cab would be in an A unit, so it would be towards the back of the A-B set...and closer to the passenger cars. In my area, the GN ran both early RS and GP diesels long-hood forward, and NP ran both short-hood forward. I believe the other 7 (CB&Q, M-St.L, CNW, CGW, CRIP, MILW, and SOO) ran their early GPs short-hood forward, and their early Alco RS's long-hood forward. So as Sheldon points out, it may just have been more how the engines were originally designed than anything else. (p.s. it would be interesting to try to do a calculation of how many early GPs were set up long-hood forward. Although I think the percentage of railroads that ran them short-hood first is higher, it could be the percentage of GPs built to run long-hood forward were higher, since two huge railroads (Pennsy and NYC) ran them long-hood first.)
Sorry, incorrect. The steam boiler in an EMD F unit "B" is in the rear just like it is in the "A" unit. But a larger water tank is up front in some of the space where the cab would be.
And for the most part, only FT locos were drawbar connected.
Yes I guess I assumed since FT-Bs had them in the 'front', they all did. But no.
The later the model of F, the less likely it was to be used with a drawbar. IIRC the union issue that caused trouble (i.e. that each unit was an engine requiring a crew) was resolved around 1950, and by then most railroads preferred couplers so they could easier mix-and-match units to get the needed horsepower. Though I think a few railroads continued with drawbars for a while - seems to me NP had A-B sets with drawbars into the 1960s?
wjstix Yes I guess I assumed since FT-Bs had them in the 'front', they all did. But no. The later the model of F, the less likely it was to be used with a drawbar. IIRC the union issue that caused trouble (i.e. that each unit was an engine requiring a crew) was resolved around 1950, and by then most railroads preferred couplers so they could easier mix-and-match units to get the needed horsepower. Though I think a few railroads continued with drawbars for a while - seems to me NP had A-B sets with drawbars into the 1960s?
Yes there were a few oddball drawbar setups after the FT's. The FT was the only model on which the drawbar was the "standard" from EMD.
The FT was designed as a drawbar connected A-B set, or A-B-A set with a short booster on a freight version. Passenger versions did not have a steam boiler in the A unit, only in the long end (effectively the front relative to the prime mover position) of the B unit along with a large water storage tank.
All other F units were designed to accommodate a steam boiler in the A unit with a 200 gallon water tank, and B units had the 200 gallon tank at the boiler and addittional 1200 gallon tank at the other end. All the tanks in the consist could be linked together.
The ATSF decided to stay with a setup similar to the FT. Since they virtually always ran 4 or more units, only B units had boilers with the standard EMD two tank setup. A units had large tanks in the rear in place of the boiler. This provided a very large water supply for the boilers in the B units, which could be anywhere from 2 to 4 units.
EMD was endlessly creative with options. If you did not get dynamic brakes you could get an additional steam boiler water tank suspended where the grids and fan would be.
And then there was the FP7/9. Longer just to have room for more water.